Figure 1.
Cold‐induced secondary dormancy induction, germination and pre‐emergence seedling growth of Beta vulgaris. (a) Cold‐induced secondary dormancy induction of seedlot KWS310. Germination of fruits at 5°C and 10°C (left panel; n = 5 plastic boxes of 100 fruits). Ungerminated fruits from the 5°C treatment were transferred to 10°C and imbibed in either H2O (control) or in the presence of gibberellin (GA4+7; right panel; n = 4 Petri dishes). The secondary dormancy of the ungerminated fruits in the control series was physiological dormancy as evident from its release by GA treatment. (b) Relation between stages of secondary dormancy, germination and pre‐emergence seedling growth. (c) Effect of seed priming and temperatures on the maximum germination percentages of contrasting sugar beet lots (for details see Figures S2b and S5b). (d) Final seedling emergence from the soil at two temperatures. (e) Seedling pre‐emergence growth rates derived from the slopes in Figure S4b. Mean values ± SEM are presented [Color figure can be viewed at wileyonlinelibrary.com]